Effect of Different Gonadotropins on In Vitro Development of Immature Caprine Oocytes

The objective of the study is to compare the embryo development from caprine oocytes matured in vitro in a medium supplemented with PMSG (Pregnant mare's serum gonadotropin) alone or in combination with hCG (Human chorionic gonadotropin). A total of 573 cumulus oocyte complexes (COCs) were matured in two treatment groups. Gr-1 (n=377) COCs were matured in TCM-199 medium supplemented with 20 IU/ml PMSG. Gr-2 (n=196) COCs were matured in TCM-199 medium supplemented with 20 IU/ml PMSG + 20 IU/ml hCG. After 27 h of maturation oocytes were fertilized in mTALP (Tyrode modified medium) and cultured in mCR2aa medium. The maturation rate in Gr-1 and Gr-2 were 88.63 and 91.78%, respectively. Similarly, cleavage rates, morula and blastocyst production were 47.13, 20.00, 10.00 in Gr-1 and 43.21, 22.85, 7.14% in Gr-2 respectively. The results indicated that oocytes matured with 20IU/ml PMSG had a good cytoplasmic maturation that allows normal embryo development up to blastocyst stage without addition of hCG. Thus, PMSG at 20 IU/ml in maturation medium can be used for in vitro embryo production.